A recent study has shown that practising yoga boosts levels of stress-busting hormones and reduces both the physical and psychological symptoms of pain in women with fibromyalgia.

Fibromyalgia, which predominantly affects women, is characterised by chronic pain and fatigue with pain focused at tender points spread around the body; other common symptoms include muscle stiffness, sleep disturbances, cognitive difficulties (known colloquially as "brain fog"), anxiety and depression, and digestive upset - many sufferers are also diagnosed with irritable bowel syndrome (IBS).

As in the related condition chronic fatigue syndrome (ME/CFS), numerous studies have shown that fibromyalgia patients have lower than normal levels of the hormone cortisol which helps the body cope with stressful situations, including pain. There is also evidence in both fibromyalgia and ME/CFS that this lack of cortisol is the result of faulty signals from the hypothalamus, the central control structure in the brain that signals the adrenal glands to produce and secrete cortisol and other stress hormones. This latest study conucted by researchers at York University, Toronto, Canada, is first to look at the effects of yoga on cortisol levels in women with fibromyalgia.

According to the study, saliva testing revealed increased levels of total cortisol in participants following a program of 75 minutes of hatha yoga twice weekly over an eight week period. Hatha yoga is a form of yoga that uses physical postures to encourage the mind to withdraw its focus from external stimuli like noise, as well as internal stimuli such as the pain experienced in fibromyalgia.

"Ideally, our cortisol levels peak about 30-40 minutes after we get up in the morning and decline throughout the day until we're ready to go to sleep," says the study's lead author, Kathryn Curtis, a PhD student in York's Department of Psychology, Faculty of Health. "Hatha yoga promotes physical relaxation by decreasing activity of the sympathetic nervous system, which lowers heart rate and increases breath volume. We believe this in turn has a positive effect on the [hypothalamic-pituitary-adrenal] HPA axis," she continued.

Although the study did not go as far as investigating specific changes in the HPA axis other than cortisol levels, it seems likely that yoga's known effects on the sympathetic nervous system would directly influence hypothalamic activity and thus hormone production in the pituitary and adrenal glands. Further research would be needed to confirm this hypothesis.

To assess the effects of the yoga program on participants' symptoms the scientists asked them to complete questionnaires with sections concerning pain, anxiety, depression, and mindfulness, both before the study began and after eight weeks of practising hatha yoga.

Significant reductions in pain and associated symptoms, as well as psychological benefits, were reported. The women felt less helpless, were more accepting of their condition, and were less likely to "catastrophize" over current or future symptoms.

"We saw their levels of mindfulness increase – they were better able to detach from their psychological experience of pain," Curtis reports. Mindfulness is a form of active mental awareness rooted in Buddhist traditions; it is achieved by paying total attention to the present moment with a non-judgmental awareness of inner and outer experiences.

"Yoga promotes this concept – that we are not our bodies, our experiences, or our pain. This is extremely useful in the management of pain," Curtis says. "Moreover, our findings strongly suggest that psychological changes in turn affect our experience of physical pain."

Additionally the study supports the paradigm of mind-body medicine. The results show that hatha yoga not only reduces fibromyalgia sufferers' subjective experience of pain and other symptoms but results in measurable physiological changes i.e. a trend toward normalisation of cortisol levels.

The current study was only small scale, involving 22 female fibromyalgia patients. The authors recommend that future studies should involve a larger number of participants and a randomised controlled trial (RCT) design to confirm their findings.

Source:Curtis K Osadchuk A Katz J (2011) An eight-week yoga intervention is associated with improvements in pain, psychological functioning and mindfulness, and changes in cortisol levels in women with fibromyalgia Journal of Pain Research 4:189–201